CAJ | 학술논문

湍流斑是近壁剪切流动中的重要现象,它们的生成和发展与流动转捩和湍流的形成密切相关.采用Navier-Stokes方程直接数值模拟和壁面脉冲模型研究平面Cou-ette流动中湍流斑的生成和演化.高精度高分辨率的三维耦合紧致差分格式被用于数值计算.探讨了平面Couette流动中湍流斑的重要特征,包括高频脉动的形成、雷诺应力的产生、扰动的急剧增长和湍流斑形状的变化,特别是流向涡的复杂演化过程.结果表明层流流动中的湍流斑具有湍流流动中一些基本特征.
단류반시근벽전절류동중적중요현상,타문적생성화발전여류동전렬화단류적형성밀절상관.채용Navier-Stokes방정직접수치모의화벽면맥충모형연구평면Cou-ette류동중단류반적생성화연화.고정도고분변솔적삼유우합긴치차분격식피용우수치계산.탐토료평면Couette류동중단류반적중요특정,포괄고빈맥동적형성、뢰낙응력적산생、우동적급극증장화단류반형상적변화,특별시류향와적복잡연화과정.결과표명층류류동중적단류반구유단류류동중일사기본특정.
Turbulent spots play a key role in the formation of the turbulence and the transition. The generation and evolution of turbulent spots using the wall impulse model in the plane Couette flow are studied by direct numerical simulation of Navier-Stokes equations. A group of three-dimensional coupling compact difference schemes with high accuracy and high resolution is used in the numerical calculation. The important characteristics of turbulent spots based on the results of examples are analyzed, including the formation of random pulse, the generation of Reynolds stress, the growth of disturbance amplitude, and the continuous change of spot shape, especially the complex evolution process of the streamwise vortices. Computational results confirm that basic properties of turbulent spots in the laminar flow are similar to those in the turbulent flow.